As shown in FIGS. 1-3, a conventional fitting tool 10 is a ratchet wrench and includes a fitting end 11 mounted on a front end thereof, a toothed retaining area 12 defined therein, a peripheral grove 13 formed on the toothed retaining area 12, and a C-type retainer 14 retained in the peripheral grove 13. A fitted tool 20 is a socket for matching with the fitting tool 10 and includes a working portion 21, a fitted end 22 over the working portion 21, a polygonal engaging portion 23 formed on the fitted end 22, and a cutout 24 defined on a respective one of the at least one side of the polygonal engaging portion 23. Thereby, when the fitting tool 10 is coupled with the fitted tool 20, the polygonal engaging portion 23 of the fitted end 22 is inserted into the toothed retaining area 12 of the fitting end 11, and the C-type retainer 14 in the peripheral grove 13 engages with the at least one cutout 24.
However, the C-type retainer 14 is made of metal material, so when the fitting tool 10 is removed from the fitted tool 20, the user has to remove the fitting tool 10 from the fitted tool 20 forcefully, thus operating the fitting tool laboriously. In addition, the C-type 14 is connected with the fitting end 11 difficultly.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.